Switch to Multisite on Local?

This didn’t work for me. I wonder if that’s because I’m using Wordpress 5.2?

  1. Adding

define( ‘WP_ALLOW_MULTISITE’, true );

has no effect.

  1. Inserting the entire script

define( ‘WP_ALLOW_MULTISITE’, true );
define( ‘MULTISITE’, true );
define( ‘SUBDOMAIN_INSTALL’, true );
$base = ‘/’;
define( ‘DOMAIN_CURRENT_SITE’, ‘ngixntest.local’ );
define( ‘PATH_CURRENT_SITE’, ‘/’ );
define( ‘SITE_ID_CURRENT_SITE’, 1 );
define( ‘BLOG_ID_CURRENT_SITE’, 1 );

generates the error:

This site can’t be reached

ngixntest.local ’s server IP address could not be found.